bullet: Streamline bundling, remove extraneous src/ folder

Document version and how to extract sources in thirdparty/README.md.
Drop unnecessary CMake and Premake files.
Simplify SCsub, drop unused one.

thirdparty/bullet/Bullet3OpenCL/RigidBody/kernels/integrateKernel.cl

@@ -0,0 +1,32 @@
+/*
+Copyright (c) 2013 Advanced Micro Devices, Inc.  
+
+This software is provided 'as-is', without any express or implied warranty.
+In no event will the authors be held liable for any damages arising from the use of this software.
+Permission is granted to anyone to use this software for any purpose, 
+including commercial applications, and to alter it and redistribute it freely, 
+subject to the following restrictions:
+
+1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
+2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
+3. This notice may not be removed or altered from any source distribution.
+*/
+//Originally written by Erwin Coumans
+
+
+#include "Bullet3Collision/NarrowPhaseCollision/shared/b3RigidBodyData.h"
+
+#include "Bullet3Dynamics/shared/b3IntegrateTransforms.h"
+
+
+
+__kernel void 
+  integrateTransformsKernel( __global b3RigidBodyData_t* bodies,const int numNodes, float timeStep, float angularDamping, float4 gravityAcceleration)
+{
+	int nodeID = get_global_id(0);
+	
+	if( nodeID < numNodes)
+	{
+		integrateSingleTransform(bodies,nodeID, timeStep, angularDamping,gravityAcceleration);
+	}
+}